---
title: "Mermaid Costume Kids — £64K/yr Amazon UK Niche (2026) - Flapen"
canonical_url: "https://flapen.com/research/uk/fashion/mermaid-costume-kids"
last_updated: "2026-07-31T23:47:25.345Z"
locale: en
meta:
description: "Niche score 45/100 · £64K/yr market · 311K searches/yr · £11.88 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:description": "Niche score 45/100 · £64K/yr market · 311K searches/yr · £11.88 avg price. Doesn't clear our bar today. Data updated Jul 2026."
"og:title": "Mermaid Costume Kids — £64K/yr Amazon UK Niche (2026) - Flapen"
---
# **mermaid costume kids**
**Skip it**
Soft demand (-27.0% this quarter) — this niche doesn't clear our bar today.
Market size 16Growth 12Conversion 22Competition 67Returns 51Price range 65Avg price 49Brand share 66Review moat 85Quality gap 70
**Review moat**
**Great****306.07**
avg incumbent reviews — the moat a new listing must climb
**Quality gap**
**Good****4.3★**
avg incumbent rating — lower means beatable quality
**Competition**
**Good****45%**
top-5 click share — leaders hold, buyers still browse
**Brand share**
**Good****65%**
top-5 brand share — brands hold most of the demand
**Price range**
**Good****£7.13–£29.58**
cheapest to priciest tracked listing — scored on the share inside $15–$100
**Returns**
**Good****3.0%**
return rate — above 5% kills the launch gate
**Avg price**
**Okay****£11.88**
avg listing price — sweet spot $15–$100
**Conversion**
**Bad****1.7%**
search→purchase rate — share of searches ending in a sale
**Market size**
**Bad****£64K**
£64K/yr · 311K searches
**Growth**
**Bad****-27.0%**
90-day search growth — must beat 0% to launch
**Signals**[** No Dominant Brand**](https://flapen.com/research/niches?market=uk&signal=no_dominant_brand "Top brand's click share < 20%")
According to Flapen's Amazon United Kingdom niche tracking, mermaid costume kids is a £64K/yr Amazon United Kingdom market (311K searches/yr). The top 5 brands hold 65% of demand. Demand peaks in Mar–Oct. Verdict: Skip it — 45/100.
Data updated Jul 23, 2026 · scored weekly · [~~How we score niches ~~](https://flapen.com/research/methodology)
## **mermaid costume kids market data**
- **Units sold / yr**
- **4K–5K**
- avg 100–250/product
- **Revenue / yr**
- **£48K–£59K**
- units × avg price
- **Conversion rate**
- **1.7%**
- **Avg BSR**
- **#429**
- **Page quality**
- **0%**
- **Prime**
- **100%**
- **Sponsored**
- **90%**
- **Out of stock**
- **10.1%**
- **Avg brand age**
- **33 months**
- **Avg seller age**
- **180 days**
## **Competition & brand share**
The top 5 products take 45% of clicks — established leaders, but buyers still shop beyond them.
**Brands**
**22 **▲rising
**Sellers**
**28**
**Top-5 brand share**
**65%**
Top 20: 98%
**Top-5 click share**
**45%**
Top 20: 78%
**Open market**
**28%**
- AOOWU16% - KumSoomliy16% - MELAND15% - BSBUY10% - Kids4ever8% - AYBUY6%
## **Demand & seasonality**
Weekly Amazon search volume, last 104 weeks — -27.0% search growth over the last 90 days.
23K18KSpike '24Spike '25Prime Day '25Spike '26Prime Day '26 seasonSepDecMarJunAugNovMarMay
Peak months: Mar, Oct · busiest ÷ quietest = 3.3×
[**Open Trend **](https://flapen.com/research/uk/fashion/mermaid-costume-kids/trend)
## **Top mermaid costume kids search terms**
- **mermaid costume kids**127K/yr-23.8%1.3% conv. - **mermaid costume**31K/yr-3.6%0.7% conv. - **mermaid dress**20K/yr+2.0%0.2% conv. - **mermaid dress for girls**9K/yr+55.5%0.4% conv. - **little mermaid costume kids**23K/yr-66.4%1.8% conv. - **ariel costume kids**22K/yr-71.7%1.7% conv. - **kids mermaid costume**10K/yr-5.8%1.2% conv. - **mermaid outfit**7K/yr+38.9%0.6% conv. - **mermaid costumes**6K/yr+26.1%0.3% conv. - **ariel costume**11K/yr-53.8%1.2% conv. [**All search terms **](https://flapen.com/research/uk/fashion/mermaid-costume-kids/search-terms)
## **Top mermaid costume kids products on Amazon**
Each bubble is one product — market share against review moat; bubble size tracks estimated sales, color grades how beatable the incumbent looks.
0%4%£3K8%£5K12%£8K16%£10K1101001K10K Reviews — right = deep review moatMarket share (90d) ≈ est. sales
Beatable (≤4.3★) Contested Strong incumbent (>4.7★)
All 24 tracked products in this niche — three views at once, no toggling.
### **Top sellers**
by 90-day click share
[1**KumSoomliy Girls Pincess Mermaid Costume Kids World Book Day Costume Dress Fancy Party Princess Dressing up Dresses Fairy Tales Childs Outfits Evening Clothes Blue with Accessories and Wig 5-6Y 130**KumSoomliy**£12.69**4.4★156 rev](https://www.amazon.co.uk/dp/B0CQLZWWDY) [2**MELAND Mermaid Costume Kids Princess Costumes for Girls Gift Aged 5-6 Little Mermaid Dress Up for Girls World Book Day (M)**MELAND**£14.24**4.0★480 rev](https://www.amazon.co.uk/dp/B0C8913F4R) [3**AOOWU Mermaid Costume Kids Mermaid Princess Dress Set with Accessories Little Mermaid Princess Costumes Fancy Dress Up for Age 3-9 Ariel Glitter Girls Costume for Halloween Cosplay**AOOWU**£11.19**4.6★494 rev](https://www.amazon.co.uk/dp/B0DL35GJTQ) [4**BSBUY Mermaid Costume Kids Little Mermaid Princess Costumes for Girls Ariel Princess Costumes Fancy Dress Up Halloween Cosplay Birthday Party World Book Day Sequin Outfit(120)**BSBUY**£9.07**3.8★31 rev](https://www.amazon.co.uk/dp/B0G5FD8SCD) [5**AOOWU Kids Mermaid Costume Set - Princess Dress with Accessories for Girls Age 3-9 Ariel Mermaid Glitter Girls Costume for Halloween & Cosplay**AOOWU**£11.16**4.6★494 rev](https://www.amazon.co.uk/dp/B0DL36V66J)
**~~View all top sellers →~~**
### **Newest**
by launch date
[**Xumplo Girls 3-Piece Mermaid Bikinis Set Kids Rainbow Fish Scale Swimming Costume with Skirt Tweens Bathing Suit 7-8 Years**Xumplo**£12.52**5 rev6mo ago](https://www.amazon.co.uk/dp/B0GF85JGKZ) [**Princess Dress for Girls Party Dress Sequin Tulle Birthday Party Wedding Clothing Blue 130cm**Luckyou**£15.77**7 rev6mo ago](https://www.amazon.co.uk/dp/B0GDXFS29H) [**JiAmy Girls Mermaid Swimsuit One Piece Swimwear with Ruffle Straps Toddler Kids Bathing Suit Scale Print Swimming Costume for Rose-Mermaid 100**JiAmy**£9.78**15 rev6mo ago](https://www.amazon.co.uk/dp/B0GCLLKR8L) [**BSBUY Mermaid Costume Kids Little Mermaid Princess Costumes for Girls Ariel Princess Costumes Fancy Dress Up Halloween Cosplay Birthday Party World Book Day Sequin Outfit(120)**BSBUY**£9.07**31 rev7mo ago](https://www.amazon.co.uk/dp/B0G5FD8SCD) [**BSBUY Mermaid Costume Kids Little Mermaid Princess Fancy Dress Up Costume with Accessories and Wig Ariel Outfit Princess Mermaid Dress Halloween Cosplay Birthday Party Mermaid Sequin Outfit(4-5 Y)**BSBUY**£10.30**167 rev1y ago](https://www.amazon.co.uk/dp/B0F9YJVDBS)
**~~View all new products →~~**
### **Trending**
90-day click momentum
[**JiAmy Girls Mermaid Swimsuit One Piece Swimwear with Ruffle Straps Toddler Kids Bathing Suit Scale Print Swimming Costume for Rose-Mermaid 100**JiAmy**£9.78**4.7★**▲ 246%**](https://www.amazon.co.uk/dp/B0GCLLKR8L) [**Xumplo Girls 3-Piece Mermaid Bikinis Set Kids Rainbow Fish Scale Swimming Costume with Skirt Tweens Bathing Suit 7-8 Years**Xumplo**£12.52**4.7★**▲ 243%**](https://www.amazon.co.uk/dp/B0GF85JGKZ) [**Nidoul Kid Girls Unicorn Rainbow Mermaid Leggings Soft Stretchy Pants High Waist Slim Tights**Nidoul**£9.35**4.6★**▲ 239%**](https://www.amazon.co.uk/dp/B07VFNMND6) [**KumSoomliy Mermaid Costume Kids Princess World Book Day Costumes for Girls Gift Mermaid Dress Up for Girls Halloween Birthday Party Gift Fairy Tales Carnival World Book Day Outfit Dresses 3-4Y 110**KumSoomliy**£10.19**4.4★**▲ 235%**](https://www.amazon.co.uk/dp/B0DBYYVB1D) [**Kids4ever Girls Dresses Mermaid Dress Summer Sleeveless Crew Neck Twirly A-Line Swing Sundress for Party Birthday 4-5 Years**Kids4ever**£11.72**4.5★**▲ 234%**](https://www.amazon.co.uk/dp/B0CS33ZC46)
**~~View all trending →~~**
## **What buyers say about mermaid costume kids**
What buyers praise and complain about, mined from review topics.
### **What buyers love **
**Size-Overall**20%
*“Fited brilliant”*
**Value For Money**20%
*“she loved it lots of accessories too included good value for money”*
**Quality-Overall**16%
*“Really good quality”*
**Color**7%
*“colour”*
**Soft Feel**6%
*“Really soft and good quality”*
**Material Quality**4%
*“breathable polyester rather than itchy materials often found in budget costumes”*
**Durability**4%
*“Daughter loves this very durable”*
**Comfort-Overall**3%
*“comfortable”*
**Stretchability/Expandability/Elasticity**3%
*“Easy Wearability: The pullover style with an elasticated waist is brilliant for quick changes”*
**Design-Overall**3%
*“The design is cute”*
### **What buyers complain about **
**Quality-Overall**52%
*“Awful quality”*
**Size-Overall**13%
*“Tail is quite long though”*
**Durability**8%
*“The crown and wand have already snapped after only a few times using them”*
**Material Quality**7%
*“Cheap material”*
**Adhesion/Stickiness**2%
*“Only downside is some of the jewellery needs glueing back together i. e the earrings”*
**Strength**2%
*“Flimsy tiara and wand”*
### **Top return reasons **
**Size-Overall**82%
**Quality-Overall**7%
**Material Quality**3%
**Defective Material/Parts**3%
**Thin**1%
**Advertised Vs Actual Product**1%
**Product Condition**1%
**Waist Fit**1%
**Stitch/Finish/Polish**1%
**Color**1%
## **Common questions**
- **Is mermaid costume kids profitable to sell on Amazon United Kingdom?**
- The niche generates £64K/yr across 42 tracked products. 0 of 9 products launched in the last 360 days are still selling. 90-day search growth is -27.0%. Flapen's verdict: Skip it (45/100).
- **How competitive is the mermaid costume kids niche?**
- 22 brands and 28 sellers compete. The top 5 products take 45% of clicks and top 5 brands hold 65% of demand.
- **What do buyers complain about in mermaid costume kids?**
- Top complaints mined from reviews: Quality-Overall, Size-Overall, Durability. The return rate is 3.0%.
- **When does demand for mermaid costume kids peak?**
- Demand peaks in Mar–Oct; the busiest month runs 3.3× the quietest.
- **What does it cost to enter the mermaid costume kids niche?**
- Listings span £7.13–£29.58; the average listing price is £11.88 (sweet spot $15–$100). The average incumbent carries 306 reviews — the moat a new listing must climb.
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